Eliminating health disparities is one of the overarching goals of Healthy People 2010. However, the focus on individual-level differences in socio-economic status and divergent health-behavior profiles have failed to fully account for the health deficits observed in minority groups. The persistency of this unexplained gap has led many to direct their attention towards differences in residential living circumstances as a contributor to racial/ethnic health disparities . Using a life-course approach that considers the socioeconomic history of an individual, we examine the causal effects of urban organization - focusing on racial segregation patterns - on adult health and mortality. We then estimate to what extent segregation contributes to health disparities among race/ethnic groups. Propensity score weighting is used to account for observed heterogeneity and to mitigate the bias due to model misspecification. Sensitivity analysis is conducted to assess the potential effect of an omitted confounding variable on estimates of significant segregation findings.